The invention relates to an implement to be mounted on a tractor for the loosening of soil, with at least one support tube which is arranged transversely of the travel direction and is composed of two parts which are connected to each other, at least two loosening bits which are rigidly, but preferably adjustably, arranged on the support tube, and connecting members hinged to the implement or to the support tube for additional implements arranged behind the loosening bit, the additional implements being provided with implement tools which are to be driven by the power take-off shaft of the tractor through at least one universal joint shaft, wherein the support tube has a tunnel-shaped recess arranged approximately behind the center of the vehicle through which there extends a universal joint shaft which connects the power take-off shaft of the tractor and the input shaft of the implement and extends at least in one vertical position of the loosening bits or of the additional implement; in accordance with German Patent Application No. 2,652,739.
Known implements of this type for the loosening of soil which can be mounted on a tractor are arranged behind the tractor wheels at a relatively short distance, so that, at an also relatively short distance behind the implement, another implement with implement tools which can be driven from the power take-off shaft of the tractor through at least one universal joint shaft can be mounted so as to be separately vertically adjustable. This facilitates the drive of the tools of the additional implement through a universal joint shaft which is simple, quite resistant to wear and does not impede the function and operation of the implements. Since the support tube of the known implement is arranged transversely of the travel direction and extends approximately horizontally and is composed of two parts between which there is arranged a tunnel-shaped recess behind the center of the vehicle through which recess there extends a universal joint shaft which connects the power take-off shaft of the tractor with the input shaft of the implement in at least one vertical position of the loosening bits or the additional implement, this support tube must be dimensioned very strong and must have in its center region several bridge-shaped reinforcements which lead to a high weight of the implement. The reinforcements mounted on the two parts of the support tube have at least two tie bars whose forward ends are rigidly connected to the mounting part of the implement on the side of the tractor and which are connected, either directly or through vertical webs, to the ends of the parts of the support tubes adjoining the tunnel-shaped recess.
At the rearward ends of the tie bars, eyes for receiving adjusting spindles are provided which are connected in an articulated manner for connecting rods which are hinged to parts of the support tube.
All these components increase the weight, the structural length and the manufacturing costs of the implement, so that it can frequently not be purchased by the owners of lightweight tractors or cannot be lifted by means of the power lift of relatively lightweight tractors.
In addition, under unfavorable conditions of use, the horizontal support tube frequently causes cloggings of the space between adjacent loosening bits with soil clods, straw, green crops, etc.
The invention solves the task of improving and simplifying the known implement to be mounted on a tractor for the loosening of soil, so that it is possible to achieve a significantly shorter structural length, a significantly lower weight and significantly lower production costs and the operation without cloggings even under unfavorable soil conditions, without negatively influencing the function and operation of the implement for the loosening of soil and of the additional, power take-off shaft-driven implement for the seedbed preparation which is to be combined with the former implement.
The invention solves this task thereby that the two parts of the support tube are arranged so as to extend to an angle relative to one another and are rigidly connected to one another at their upper ends, so that they together form a triangle which is open toward the bottom and at whose top there is arranged a coupling device for at least one upper link and at whose lower ends there are arranged coupling devices for at least one draft link each, these coupling devices also serving as support pockets for the support arm of a loosening bit.
The connecting members preferably are constructed as brackets fastened to the support tubes for implement tools which are arranged behind the loosening bits and are to be driven by the power take-off shaft of the tractor through at least one universal joint shaft, the brackets being releasably connected to screw-on angle-sections mounted on the frame of the implement.
In accordance with another feature of the invention, the support arms of the loosening bits are fastened in the support pockets so that they are easily releasable and vertically adjustable.
In accordance with another feature of the invention, the coupling bolts can be placed in bores of the support pockets so that they are easily releasable and removable.
When the loosening bits are arranged at a greater distance, the three-point coupling serves as a mounting stand of the implement on the power lift of the tractor, and the brackets, in the state of dismounting from the implement, releasably connected to one another through an intermediate frame serving as a stiffening member.